Conventional vehicle headlights can include a lighting unit dedicated for forming a low-beam light distribution pattern (so-called as a low-beam lighting unit) and/or a lighting unit dedicated for forming a high-beam light distribution pattern (so-called as a high-beam lighting unit), such as those disclosed in Japanese Patent Application Laid-Open No. 2005-141919 (or corresponding U.S. Patent Application Laid-Open Publication No. 2005094413A1).
In such a vehicle headlight, the low-beam lighting unit can be lit to form a low-beam light distribution pattern while the high-beam lighting unit can be lit to form a high-beam light distribution pattern.
In the vehicle headlight described in Japanese Patent Application Laid-Open No. 2005-141919, the low-beam lighting unit and the high-beam lighting unit are constituted of two physically separated lighting units, and the light source is required for each lighting unit. As a result, costs and assembly steps for light sources can be increased.